diff --git a/vendor/github.com/spf13/pflag/ip_slice.go b/vendor/github.com/spf13/pflag/ip_slice.go
new file mode 100644
index 0000000..7dd196f
--- /dev/null
+++ b/vendor/github.com/spf13/pflag/ip_slice.go
@@ -0,0 +1,148 @@
+package pflag
+
+import (
+	"fmt"
+	"io"
+	"net"
+	"strings"
+)
+
+// -- ipSlice Value
+type ipSliceValue struct {
+	value   *[]net.IP
+	changed bool
+}
+
+func newIPSliceValue(val []net.IP, p *[]net.IP) *ipSliceValue {
+	ipsv := new(ipSliceValue)
+	ipsv.value = p
+	*ipsv.value = val
+	return ipsv
+}
+
+// Set converts, and assigns, the comma-separated IP argument string representation as the []net.IP value of this flag.
+// If Set is called on a flag that already has a []net.IP assigned, the newly converted values will be appended.
+func (s *ipSliceValue) Set(val string) error {
+
+	// remove all quote characters
+	rmQuote := strings.NewReplacer(`"`, "", `'`, "", "`", "")
+
+	// read flag arguments with CSV parser
+	ipStrSlice, err := readAsCSV(rmQuote.Replace(val))
+	if err != nil && err != io.EOF {
+		return err
+	}
+
+	// parse ip values into slice
+	out := make([]net.IP, 0, len(ipStrSlice))
+	for _, ipStr := range ipStrSlice {
+		ip := net.ParseIP(strings.TrimSpace(ipStr))
+		if ip == nil {
+			return fmt.Errorf("invalid string being converted to IP address: %s", ipStr)
+		}
+		out = append(out, ip)
+	}
+
+	if !s.changed {
+		*s.value = out
+	} else {
+		*s.value = append(*s.value, out...)
+	}
+
+	s.changed = true
+
+	return nil
+}
+
+// Type returns a string that uniquely represents this flag's type.
+func (s *ipSliceValue) Type() string {
+	return "ipSlice"
+}
+
+// String defines a "native" format for this net.IP slice flag value.
+func (s *ipSliceValue) String() string {
+
+	ipStrSlice := make([]string, len(*s.value))
+	for i, ip := range *s.value {
+		ipStrSlice[i] = ip.String()
+	}
+
+	out, _ := writeAsCSV(ipStrSlice)
+
+	return "[" + out + "]"
+}
+
+func ipSliceConv(val string) (interface{}, error) {
+	val = strings.Trim(val, "[]")
+	// Emtpy string would cause a slice with one (empty) entry
+	if len(val) == 0 {
+		return []net.IP{}, nil
+	}
+	ss := strings.Split(val, ",")
+	out := make([]net.IP, len(ss))
+	for i, sval := range ss {
+		ip := net.ParseIP(strings.TrimSpace(sval))
+		if ip == nil {
+			return nil, fmt.Errorf("invalid string being converted to IP address: %s", sval)
+		}
+		out[i] = ip
+	}
+	return out, nil
+}
+
+// GetIPSlice returns the []net.IP value of a flag with the given name
+func (f *FlagSet) GetIPSlice(name string) ([]net.IP, error) {
+	val, err := f.getFlagType(name, "ipSlice", ipSliceConv)
+	if err != nil {
+		return []net.IP{}, err
+	}
+	return val.([]net.IP), nil
+}
+
+// IPSliceVar defines a ipSlice flag with specified name, default value, and usage string.
+// The argument p points to a []net.IP variable in which to store the value of the flag.
+func (f *FlagSet) IPSliceVar(p *[]net.IP, name string, value []net.IP, usage string) {
+	f.VarP(newIPSliceValue(value, p), name, "", usage)
+}
+
+// IPSliceVarP is like IPSliceVar, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) IPSliceVarP(p *[]net.IP, name, shorthand string, value []net.IP, usage string) {
+	f.VarP(newIPSliceValue(value, p), name, shorthand, usage)
+}
+
+// IPSliceVar defines a []net.IP flag with specified name, default value, and usage string.
+// The argument p points to a []net.IP variable in which to store the value of the flag.
+func IPSliceVar(p *[]net.IP, name string, value []net.IP, usage string) {
+	CommandLine.VarP(newIPSliceValue(value, p), name, "", usage)
+}
+
+// IPSliceVarP is like IPSliceVar, but accepts a shorthand letter that can be used after a single dash.
+func IPSliceVarP(p *[]net.IP, name, shorthand string, value []net.IP, usage string) {
+	CommandLine.VarP(newIPSliceValue(value, p), name, shorthand, usage)
+}
+
+// IPSlice defines a []net.IP flag with specified name, default value, and usage string.
+// The return value is the address of a []net.IP variable that stores the value of that flag.
+func (f *FlagSet) IPSlice(name string, value []net.IP, usage string) *[]net.IP {
+	p := []net.IP{}
+	f.IPSliceVarP(&p, name, "", value, usage)
+	return &p
+}
+
+// IPSliceP is like IPSlice, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) IPSliceP(name, shorthand string, value []net.IP, usage string) *[]net.IP {
+	p := []net.IP{}
+	f.IPSliceVarP(&p, name, shorthand, value, usage)
+	return &p
+}
+
+// IPSlice defines a []net.IP flag with specified name, default value, and usage string.
+// The return value is the address of a []net.IP variable that stores the value of the flag.
+func IPSlice(name string, value []net.IP, usage string) *[]net.IP {
+	return CommandLine.IPSliceP(name, "", value, usage)
+}
+
+// IPSliceP is like IPSlice, but accepts a shorthand letter that can be used after a single dash.
+func IPSliceP(name, shorthand string, value []net.IP, usage string) *[]net.IP {
+	return CommandLine.IPSliceP(name, shorthand, value, usage)
+}